Central Nervous System Disorders

The central nervous system plays an important role in controlling human behavior. The central nervous system comprises two main components: the brain and the spinal cord. It is held within the dorsal cavity, the brain in the cranial cavity and the spinal cord in the spinal cavity. The nervous system is built up of nerve cells, called neurons, which allow the various parts of the body to coordinate with each other through the brain and the spinal cord.

A person suffering from any type of central nervous system disorder, can be identified due to the symptoms such as delay in developmental milestones, changes in activity, reflexes, or movements, abnormal head growth, variations in level of consciousness or mood, muscle rigidity, tremors, or seizures, severe headaches, visual changes and lack of coordination.

Disorders of the Central Nervous System

• Transverse Myelitis
  It is an inflammatory attack in the spinal cord with no brain or optic nerve involvement. It is mainly a monophasic condition where the attack occurs only once. In rare cases, the patient may suffer from more than one inflammatory attack in their spinal cord, this condition is called Recurrent TM. Some patients may also suffer from an inflammatory attack in the spinal cord along with an underlying rheumatic disorder like Lupus or Sjogren's syndrome. Since the underlying cause is unknown, it is also referred to as Idiopathic Transverse Myelitis. TM symptoms develop quickly within a few hours to a few weeks. The spinal cord is responsible for carrying motor nerve fibers to the limbs, trunk and sensory fibers from the body back to the brain. Inflammation within the spinal cord disrupts these pathways and causes symptoms like limb weakness, sensory disturbance, bowel and bladder malfunction, back pain and radicular pain.
• Neuromyelitis Optica or Devic's Disease: It involves inflammatory attacks in the spinal cord and optic nerve. A person suffering from neuromyelitis optica (NMO) is at a higher risk for multiple attacks of spinal cord inflammation or optic neuritis, or both. The main symptoms of NMO are loss of vision and spinal cord dysfunction. The visual impairment is manifested by visual field defects, loss of color vision or decreased visual activity, etc. The spinal cord dysfunction causes muscle weakness, reduced sensation, loss of bladder and bowel control. Patients may also suffer from an acute and severe spastic weakness of the legs (paraparesis) or all four limbs (tetraparesis).
• Multiple Sclerosis: It involves an inflammatory attack that may occur anywhere within the central nervous system i.e., brain, spinal cord or optic nerves. The disease usually occurs in young adults, and is more common in females. Most of the patients have brain lesions during the onset of the disease. A person suffering from multiple sclerosis can be observed with symptoms like muscle spasms, dysarthria, lack of coordination and balance (ataxia), hypoesthesia and paraesthesia, visual problems and loss of bladder and bowel control. It's relapses are quite unpredictable and happen without any warning or obvious inciting factors.
• Alzheimer's Disease: It is a progressive, neurodegenerative disease that occurs in the brain and is a common form of dementia. It reduces the generation of certain brain chemicals which are essential for communication between the nerve cells like norepinephrine, soamtostatin, acetylcholine and serotonin. The causes for the disease are not completely known but abnormal protein deposits in the brain, environmental or genetic factors are some suspected causes. Alzheimer's disease leads to impaired memory or judgment, language deterioration, emotional apathy and impaired visiospatial skills.

Some other disorders are Parkinson's disease, epilepsy, amyotrophic lateral sclerosis (ALS), Huntington's chorea, etc. Presently there's no cure for these disorders but treatments like medication, rehabilitation activities, clinical trials and assistive technology can be beneficial for the patients.